Low-pressure alarm signal



March 31, 1953 E. G. ELLIS LOW-PRESSURE ALARM SIGNAL 2 SHEETSSHEET 1 Filed Jan. 13 1951 Earl 6 Ellis INVENTOR March 31, 1953 E. e. ELLIS LOW-PRESSURE ALARM SIGNAL Filed Jan. 15, 1951 2 SHEETS-SHEET 2 INVENTOR.

n E a M v E Patented Mar. 31, 1953 UNITED STATES PATENT Omar lEar'l :6. Ellis, Fort Worth, .'I.ex., *assignor to IMidifiontinent Supply :Company, Elna, Earl; Worth, fllexsaromomtinno! Delaware Apnlieationifanuarr 13 195 1, :SeriaIiNo. fzili9ig4i' immune. (onus-flu).

This "invention relates .to -:and useful r111 movements in alarm signals and more gparticularly to signal "devises :foriindioatiiig 'eljow :Ilu'id' pressure.

One object 01' "the "invention is to provide an improved'alarm signal foraudibly indicating the *fallofa pressure belowia-predeterminedpoint and arranged so as'to "be rendered inoperative whenever' de's'ired.

ltnother object ofthe- "invention is "to provide an improved alarm signallhavingmeans respong 'sive tothe pressure of =a Ffluid for 'eontrolling jfith'e': "operation o1 an alarm and means 'for h'dldin'g the pressure :responsive *means against move' ment to"preventoperation of the alarm.

Aparticular object or the invention is to provide an improved alarm signdl, "of the character described, which includes a pressure--responsive member resiliently urged in one direction "for iadmitting'an-auxiliary pressure'iluidto an alarm ende posed to "a fluid so "as "to be moved "in the opposite direction by the pressure 0f =the latter fluid rm: preventing communication of the auxiliarytflu'id with the alarm-except "when the pressure or *said latter fiu'id is less than :a predetermined minimum.

An impor'tant object of theinvention isto provide animproved alarm signal, .of the characterdescribed, wherein-means is connected {to :the :pressure responsive .member for moving and .iholdingsaidrmenib 'eriin an inoperative position -to 'prevent aetuation of the alarm in the absence. o! adequate :pressure, said holding :meansiibeing vrendeiiediinoperative when the pressure of "the iflui" exceeds :a fpredetermined minimum. 7

.- urthersobiectotfthe invention is' to-provide ran improved alarm .signal, of the character tie-- scribed, wherein the molding means includes an =-unoalanoed :element :having pivotal sconneotion mith thefpressure responsivetmember 'and adapted to be swung manually for moving andrholding saidnnember "inits inoperative position, the ele inent being :swung inithe :opposite direction and :rendered i inoperative "upon restoring :of the :pressure. ofrtheiiuidsand additional "movement ofssaid member.

with the invention, with its pressure-:responsive member held in inoperative rinsed mositiom ill) Atonstructiondesigned'to "carry Q1115 the #vention will .rbe i hereina'fter described together with other features of thezinvention. 1 t

The invention will be more readily understood from .a reading rof the 'followingaspecification and eby reference .1110 the accompanying drawings, wherein ran wexample lot the invention is shown, :and wherein:

Fig. *2 'is -a perspective :view or the upperiportionof the signal, showing the -parts 'inythe zon- 'erative open position :of the member,

Fig. 3 is :an enlarged view, similar to. Fig. ;1-, showing the pressure-responsive member in its open "operative position,

Fig. 4 is a horizontal, scrossesectional wiew, taken 'on 'the'line ll-Ieof Fig.3, :and

"Fig. :5 .is :a view, i similar 'to sand takeniat :right angles "to *Fig. "3. i

'In the -'drawings, the "numeral designates the substantially upright :body 'or housing .(Of 'a low pressure alarm signal :having a mounting bracket H and. 'a :chamber the form-oi .an axial, cylindrical boreor :cylinder I12. The ride :vi'ce is adapted to vbe mounted on or adjacent an internal-combustion engine that shown) :01 other mechanism having oil :or :other 'fluid under pres-'- sure, such :as in a lubrication system. oil 'or other fluid line I3 is connected in san :axial, screw-threaded inlet -or port 1 4 :provided in the lower end of thelbody 110 "in scommunication with the cylinder I2, whereby theipressure of the 'oil or fluid is exerted "upon a ipressure responsive "member IS, in the .:form :of apiston orplunger, reciprocally "mounted in said goylinder. :will xbeexplained, the piston .115 :is adapted :to non- :trol'the operation of "an alarm devise it, "which is preferably audible and in the form of a whistle, by establishing 33113.6 shutting on "communication between the whistle and -'a source of air or otheriluid under' 'pressure, "such gasiline I 1. "Radial, screw-threadedQ ports ll! "and F9 are formed in intermediateflportion of the body "for connecting the whistle "I'G'and line 111, respectivejly, thereto in communication with the cylinder and the ports are preferably opposed "with the ngtlet port 18 being disposed above "the inlet port .A flanged bonnet or cap '20 is :screw threaded the-upper 'end of the cylinder andan axial rodor stem 2 l projects upwardly fromthe piston .throughfthe cap, tFornslidahly receivingthe stem 2!, the .cap 20 :has an axial, depending. uide sleeve 22 whiehtis externallyescrewethreadedand carries an adjusting nut- 23, :A: coiled-spring 24 confined between theinut and the upper :endof the piston surrounding relation :to vthe-stem"and guide sleeve for maintaining said @piston :in the :hosition showninfigid, Elhe'forceoi theesprine rig. :1 :is "39 transverse, ve'rtical,.isectiona1 wiew .i'ss may be' varie -hyca instiiieuthemutzza antiwar-Less to said nut is obtained by removal of a cover plate 25 (Fig.

An annular, external groove or recess 26 is formed in the piston and adjacent its upper end and is of suflicient width to establish communication between and connect the ports I8 and I9 when said piston is in its lower position (Figs. 3 and 4). Due to this communication, the line I I is connected to the whistle I6 and the pressure of the fluid in said line operates said whistle. Since the lower end of the piston is exposed to the pressure of the oil or fluid in the oil line, said piston is raised when said pressure exceeds the force of and compresses the spring 24. In this position of the piston, substantially as shown in Fig. 1, the port I9 is closed by the lower p'or-- tion of said piston whereby said port is shut ofi from communication with the port I8. Thus, the whistle or alarm is inoperative when there is sufficient pressure in the line I3 and is operated only when said pressure drops below a predetermined amount which is controlled by the force of the spring and the adjustment of the nut 23.

Suitable sealing rings 21, such as O-rings, are

carried by the piston above and below the groove 26 for preventing leakage of the operating pressure past said piston into the cylinder I2. It is noted that the lower ring 21 is disposed between the ports I8 and I9 when the piston is in its raised position. Similar sealing rings 28 are carried by the lower portion of the pistonfor confining the fluid in the oil line to the lower portion of the cylinder and are always disposed below the port I9. For sealing ofi between-the stem 2I and sleeve 22, a similar sealing ring 29 is carried by said stem.

In order to prevent operation of the alarm signal or whistle when there is no pressure in the oil line, such as when an internal combustion engine is not operating, means are provided for moving and holding the piston in a raised position with its groove 26 above and out of communication with the port I9 (Fig. 1). This means includes an unbalanced element or lever 30 pivotally connected to the upper end of the stem 2| which projects through the cap 20 and which has an enlarged head 3I overlying said cap. A yoke 32 is formed on the inner end of the lever 30 for receiving the head 3I and is connected thereto by a transverse pivot pin 33. The legs of the yoke 32 extend beyond the head and function as a fulcrum for raising the head and its stem as well as the piston I 5 upon upward swinging or pivotal movement of the lever. 1

33 are preferably rounded and project. beyond the yoke-for engagement in upright guide grooves or channels 36 formed in opposed ears or lugs 31 which project upwardly from the cap 20, as is most clearly shown in Figs. 2 and 5. Suitable stops or shoulders 38 are formed on the head 3| for limiting the movement of the lever and an arcuate surface 39 is provided between the shoulders for coacting with said lever. The latter is preferably angular and includes a weighted handle portion 40 for swinging said lever downwardly from the position shown in Fig. 1 to the position shown in Fig. 3.

'Whenever desired, the lever 30 may be swung upwardly to raise the piston to the position shown in Fig. 1 whichmoves the recess 26 out of communication with the port I9 and thereby shut off the flow of pressure fluid to the whistle IS. The lever and piston remain in this position until the pressure in the oil line I3 is suflicient to overcome the force of the spring 24. In the position shown in Fig. 1, the upper end of the piston is spaced from the lower end of the guide sleeve 22 whereby additional upwardmovement of said piston is permitted. Upon this additional upward movement, the yoke legs of the lever are moved out of engagement with the bearing plate 35 and the weight of the handle portion 40 causes downward swinging of said lever. After being swung downwardly, the lever or holding means is inoperative whereby the movement and position of the piston are controlled by the pressure of 'the oil line.

When there is suflicient pressure, the piston is forced upwardly to move the recess 26 out of communication with the port I9 and shut off the flow of air-or other pressure fluid to the port I8 and its whistle I6. If the pressure in the oil line falls below a predetermined amount, the force of the spring 24 moves thepiston downwardly to the position shownin Fig. 3 whereby the recess 26 establishes communication between the ports I9 and I8 and permits the flow of air or other pressure fluid to the whistle. As has been explained, upward movement of the piston by thelever or the-pressurein the oil line shuts 01f the whistle-actuating fluid.-

The foregoing description of the invention is explanatory thereof and various-changes the .size, shape and materials, as well as in the defluid supplying means communicating with the inlet, pressure-responsive means in the chamber controlling communication between said inlet and outlet and resiliently held in communicatingposition for operating the signal device, said chamber having a pressure fluid inlet for exposing the pressure-responsive means to a fluid under pres.- sure whereby the same is moved to and "held in non-communicating position by a predetermined pressure of the fluid, and means havin con 1160131011 with said pressure-responsive means for .movmg and holding the same in non-communicating position to prevent operation of said: signal device when said fluid drops below the predetermined pressure, said pressure-responsive means being movable by the predetermined pressure of said fluid when held in non-communicating position to release and render the holding means inoperative. i

2. A low pressure alarm signal including, a

chamber having an inlet and an outlet, a signal device communicating with the outlet,'pressure fluid supplying means communicating with the inlet, pressure-responsive means in the chamber controlling communication between said inlet and outlet and resiliently held in communicating position for operating the signal device, said chamber having a pressure fluid inlet for exposing the pressure-responsive means to a fluid under pressure whereby the same is moved'to and held in. non-communicating position by a predetermined pressure of the fluid, and manual means connected to said pressure-responsive means to permit manual movement and retaining of the same in non-communicating position so as to prevent operation of said signal device when said fluid drops below the predetermined pressure, said pressure-responsive means being movable by the predetermined pressure of said fluid when held in non-communicating position to release and render inoperative the manual means. r

3. A low pressure alarm signal including, a chamber having an inlet and an outlet, a signal device communicating with the inlet, pressureresponsive means in the chamber controlling communication between said inlet and outlet and resiliently held in communicating position for operating the signal device, said chamber having a pressure fluid inlet for exposing the pressureresponsive means to a fluid under pressure whereby the same is moved to and held in noncommunicating position by a predetermined pressure of the fluid, and a weighted element pivotally connected to and movable with said pressure-responsive means and adapted to be swung relative thereto for moving and holding the same in non-communicating position so as to prevent operation of said signal device when said fluid falls below the predetermined pressure, said pressure-responsive means being movable by the predetermined pressure of said fluid when held in non-communicating position to release the element and permit reverse swinging thereof whereby said element is inoperative.

4. A low pressure alarm signal including, a cylinder having a pair of ports in its wall, a

signal device communicating with one port, a source of pressure fluid communicating with the other port for operating the signal device, a pressure-responsive member in the cylinder controlling communication between the ports and resiliently held in a position establishing communication between said ports, an inlet in one end of said cylinder for exposing the member to a fluid under pressure whereby said member is moved to and held in a position shutting off communication between said ports by a predetermined pressure of the fluid, and manual means having connection with said member to permit manual movement and retaining of said member in a position shutting off communication between said ports when said fluid falls below the predetermined pressure, said member being movable by said predetermined pressure when retained in the last-mentioned position to release said manual means and render the same inoperative.

5. A low pressure alarm signal including, a cylinder having a pair of ports in its wall, a signal device communicating with one port, a source of pressure fluid communicating with the other port for operating the signal devices, a pressure-responsive member in the cylinder controlling communication between the ports and resiliently held in a position establishing communication between said ports, an inlet in one end of said cylinder for exposing the member to a fluid under pressure whereby said member is moved to and held in a position shutting off communication between said ports by a predetermined pressure of the fluid, and an unbalanced element pivotally connected to and movable with said member and adapted to be swung relative thereto for moving and holding the same in a position shutting off communication between said ports when said fluid drops below the predetermined pressure, said member being movable by the predetermined pressure of said fluid when held in the last-mentioned position so as to release the element and permit reverse swinging of said element to its inoperative position.

6. A low pressure alarm signal as set forth in claim 5 wherein the element includes fulcrum means for moving and holding the pressureresponsive member in the last-mentioned position.

7. A low pressure alarm signal including, a cylinder having a pair of ports in its wall, a signal device communicating with one port, a source of pressure fluid communicating with the other port for operating the signal devices, a spring pressed piston in the cylinder controlling communication between the ports and held in a position establishing such communication, an inlet in one end of said cylinder for exposing the piston to a fluid under pressure whereby said iston is moved to and held in a position shutting ofl communication between said ports by a predetermined pressure of the fluid, and an unbalanced lever pivotally connected to and movable with said piston and adapted to be swung relative thereto for moving and holding the same in a position shutting off communication between said ports when said fluid drops below a predetermined pressure, said piston being movable by the predetermined pressure of said fluid when held in the last-mentioned position so as to release the lever and permit reverse swinging thereof to its inoperative position.

8. A low pressure alarm signal as set forth in claim 7 including, a stem carried by the piston and projecting through the end of the cylinder opposite the inlet for pivotal connection with the lever, said lever having fulcrum means for moving and holding the stem outwardly of said cylinder and thereby move and hold said piston in the last-mentioned position.

EARL G. ELLIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Nmnber Name Date 754,847 Clark Mar. 15, 1904 989,460 Westphal Apr. 11, 1911 1,187,693 Woolley June 20, 1916 1,994,958 Moffett Mar. 19, 1935 2,441,094 Alderfer May 4, 1948 

